Archived Version

Introduction

When it has been raining recently, the stream both gets higher, and flows faster. After heavy rainfall, the river doesn't rise for 36 hours. This is because water in the river's catchment area has to percolate through the ground like a sponge to get there. In prolonged rainfall, the ground is already water-logged, and rainfall quickly turns into 'run-off' and drains straight into the river. It’s worth mentioning that if there is rainfall east – downstream - of Oxford, it won't show in the levels of the Isis. Likewise, if there is rainfall west of, but not in, Oxford - we can still expect to see a spike in river levels a couple of days later.

Wind is also a factor when OURCs make a stream assessment; most notably at the green-blue boundary. Wind strength is proportional to the surface area of the boat on a particular side; head and tail winds affect speed by a small amount, while cross-winds will quite severely blow the vessel off the course it wishes to make.

The Environment Agency have a way of dealing with high waters - the weirs. Weirs have gates that can alter the amount of water let through it. If the weirs are fully open (or 'drawn'), water will drain away from the Isis much faster; however, the stream speed will sharply increase. If the weirs are mostly closed, perhaps being mindful of not flooding settlements further downstream, the river won't be as fast, but take longer to go back down to low stream.

The weirs we are most affected by are the ones at Osney Lock, Iffley Lock, and the weirs down the side-channels at Longbridges (Hinksey). The Isis flag status is just a guideline as to the river's difficulty, and we have to inspect the local conditions and react accordingly to them.

Flag Restrictions

OURCs states that the flag dictates who must not go out, and not necessarily who can go out. As part of the club's risk assessment each time before they boat, they must assess the conditions. For the most part, the flag is an adequate guideline. In times where the side channels are pulling particularly fast, you might want to abandon an outing, especially if you have a novice crew. It is up to whoever is in charge to judge whether conditions are safe for boating. As an experienced or senior cox, you are legally responsible for the safety of the crew on the water.

Under blue flag, no novice coxes are permitted on the water (so X/S only). As a corollary, you do not need a bank rider for outings under blue flag. However, it will often help, especially if the crew is novice, or the cox isn't brilliant at landings.

Under amber flag, only 'senior' crews may boat. A senior crew, as defined by OURCs, consists of:

A senior cox

For an 8+, 4 or more people must have had a year's worth of rowing experience; all 8, however, must have had a whole term's experience

For a 4+, all four oarsmen must have a year's worth of experience

A bankrider at all times, who has a throw line, and a mobile phone pre-programmed with the number of the Iffley Lock Keeper (01865 777 277) in case of emergency.

Other crews can be designated senior status at the discretion of the OURCs secretary - feel free to enquire if you think this is applicable. As well as this:

Crews may not pass through the locks

Crews must turn ealy at Haystacks - there is a big red girder on the TOWPATH side about 100m downstream of Donnington bridge. You may spin at any point beyond that (being mindful of any other crews out on the water); you should aim to start spinning before Haystacks corner, and at no point drift downstream of the green flag spinning post.

Boating

As obvious as this is, it is worth mentioning - when you row upstream, you are rowing against the stream, and will go more slowly. When you are going downstream, you are rowing with the stream, and will go faster.

When your crew are getting in the boat, it is important to keep good control of their blades. They must hold on to them at all times. Ensure also that they are tilted with the concave side of the blade facing downstream. This will allow the water to run under it, as opposed to dragging the hatchet under the water (which risks capsizing).

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Boating from Boathouse Island:

As is usual from BHI, you must boat facing upstream. As the cox, you should hold on to the rigger that is furthest upstream - bow's rigger for a stroke-rigged boat. Be aware that because the stream is fast, pointing your bows towards the towpath will result in the boat beginning to spin. If you find that you are spinning, your best bet is to get bow and 3 to hold it up, and stroke side to row on. This has the effect of placing you more towards the centre of the river, so that deviating away from upstream by a small amount will make the stream restore you to the correct orientation.

Boating from Longbridges:

When pushing off from Longbridges, you must be very careful to avoid being pulled down the weirs. Take into account the following points:

You may choose to boat upstream (towards Univ boathouse) or downstream (towards the Gut). Boating upstream is safer if you have a less experienced crew. It is possible to boat downstream, but be aware that if you are not on your toes, you will get drawn under the bridges. You must also row with the full crew once you get to the Gut.

When the oarsmen are getting blades, make sure you hold on to a rigger. If you let the boat go, it will go down the weir. However, the stream is fastest in the centre, and so it will rotate the boat as well if it's not parallel to the stream flow. We can use this to our advantage later, but for now, make sure you hold on to the rigger on the pontoon that is furthest upstream (either 2 or 7).

You can easily spin the empty shell on the water so that you are pointing upstream – provided there’s nobody you will obstruct! Push the bow-side rudder string fully forwards. Get someone to shove the bows out, while you bring the stern round. Hold the stern out as far as you can, as this is fastest. Make sure the wind is pointing the correct way, as this has a large effect on an empty boat. Don’t let go! Also, have someone handy with a blade to drag it in if needs be.

Boating upstream is just as you would under green flag. Just don't dawdle too much, and make sure you get 2 and 4 to push off the pontoon a bit more than 6 and stroke to point you in the right direction.

If you are boating pointing your bows downstream, make sure you are as much of the way UP the pontoon as possible. This gives you plenty of room in which to get away from the side-channels. Push off from your bowside, and as soon as possible, get bow and 3 to row on. This is where you need a crew who know what they are doing. If they're novice, bow will take a stroke before 3 can, and then 3 will start rowing while bow is going up the slide. Then there'll be an awkward five seconds while bow tries to follow 3, and 3 tries to get in time with the rhythm that bow established. Before you know it, you're going down the side-channels parallel to the bridge, which is bad. Soon after, get the whole of bow-side to join in.

Once you are pointing towards the gut, you may row as normal, but be aware that you will be taking a bad angle into it. Rowing with stroke side and 7 (and optionally 5) is a good way to quickly change the direction of the boat. If there are no crews behind you, then you do not have to row full crew through the gut.

Boating from Univ:

Crews boating from Univ must boat downstream. As the cox, you should hold on to the rigger that is furthest upstream - 7's rigger for a stroke-rigged boat. Make sure (as outlined earlier) - that crews feather their blade backwards while getting in. You should aim to point your bows slightly away from the towpath when pushing off - if your stern swings out, you will start to spin.

Boating from Isis Boathouse:

Crews under blue or amber flag must point upstream when boating; as the cox, you should hold on to the rigger that is furthest upstream - bow's rigger for a stroke-rigged boat. Be aware that because the stream is fast, pointing your bows towards the city side will result in the boat beginning to spin. If you find that you are spinning, your best bet is to get 2 and 4 to hold it up, and bow side to row on. This has the effect of placing you more towards the centre of the river, so that deviating away from upstream by a small amount will make the stream restore you to the correct orientation. This will aid you while going through the spinning area.